Hi everyone, Not sure if this is the right spot for this. I just had this 350 rebuilt a few years back. Nothing special, headers, honed bores, ta284 cam, crank resurfaced, new lifters, new pushrods, new bearings, new rocker shaft. It's fuel injected (sniper) so there is a tick from the the fuel *injectors (I misspoke in the video while over the engine). The tick in question can be heard slightly several feet from the car and when under the front end like in the video. What could this sound be. It's not like a metal hammer sound like rod knock, and not as sharp and ticky as a lifter or cam... Any help is greatly appreciated. Thanks! https://youtube.com/shorts/FkXurfKYS4E?feature=share
Hmmmmm. Are you able to narrow down the area its coming from? Use a stick from engine area to your ear? Maybe fan clutch? Doesn't sound catastrophic. Change with higher rpm? I might suggest removing belts to see if it is an accessory.
I used a stethoscope to check around the block and it's seemingly more difficult to distinguish while using it. It's definitely not the oil pump, water pump, alternator, efi/intake related. It does sound slightly irregular. And it's hard to tell from all the other noise, but it does change with higher rpm, although it does not get louder.
If it’s a auto trans car I have heard sounds like that coming from a cracked flex plate and due to the engine bay confines it can sound like its coming from the front. first off though I would pull off one plug wire at a time and confirm that is not the beginning of a rod bearing issue or wrist pin. note that a wrist pin will make a double slap like a tambourine, once at the top of the stroke and once at the bottom. many a metallic noise has been found to be a Exh leak, so don’t rule that out either!
I will do this and record it this week. My last motor had some crazy lifter tick and ate the camshaft and this doesn't seem to sound like that, but I'll check it out and let you all see.
I really do hope it is a flexplate - I have a backup from TA. Along with the video pulling the covers off, I'll add one with the plug test and another with accessories removed. About a year ago I did the plug test and it was pretty inconclusive, the sound was still there. Just for reference, not sure if it helps any, the motor has been running strong and has had this sound for 2/3 years ever since the rebuild (maybe 6000+ miles) . It has pretty much stayed the same in volume level. Oil pressure has also stayed the same since the rebuild. Oil pressure when warming up is 60-80 Oil pressure hot and driving is 40-60 Hot idle is 25
Post rebuild noise makes me thing of a few things: 1.) Someone already mentioned it, but a shot harmonic balancer can make the pully wobble a tiny bit and that can make a similar clicking noise. Sounded VERY familiar. 2.) If a new fan got put in, check to make sure the fan bolts are the right length. Some aftermarket fan necks that bolt to the pully are very very close, but don't actually tighten down on the lock washers all the way. I lost 2 water pumps this way (i.e. the fan was wobbling and that, along with coolant on the back of the water pump rusting the bolt holes did the bearings in. Added a Hexcoil and got new bolts ...voila, no more ticking. I like the idea of pulling the fan off and using replacement bolts for the pully and starting it/running it without the fan for just a few moments to see if the sound persists. In the video it does look like the pully has a slight wobble to it. But I could just be imagining that! Someone else mentioned wrist pins or flex plate. If you think that's the case I'd use a stethoscope on the oil pan and then the transmission cover that's right behind the oil pan that covers the flex plate. That should help you dial it in. Good Luck and Stay Safe!
I second the idea of running it without belts for a test. Eliminate the fan, water pump, alternator, PS and AC along with maybe the damper.
Check the bolts on your torque converter/flexplate. I've had them loosen and it sounded just like that.
Update: Tonight I was able to pull plugs and check around with a stethoscope on each cylinder. Plug test was pretty inconclusive again so I'll have to try it with the accessories removed. Things to note, the noise was more noticeable when temp got up to 165+ and the oil temp dropped to it's usual hot idle. With the stethoscope I checked all around the engine and transmission again.. I checked the top of every cylinder too. On cyl 7 I heard a tapping that sounds similar and behaves similar to the one I'm hearing outside the motor. I then checked the bottom end by the pan and up along the block sides where the number 7 rod meets the crank and only heard smooth whirling from the bearings. Still the sound from the video is most present right where the camera was and specifically at the front of the engine...so I'll still have to rig up the engine to run off the battery this weekend. If it is coming from the top area of cylinder 7, I think my options are wrist pin play or pinging. Not sure about piston slap or wobble.. I haven't ruled out the flexplate either because I can hear a moderate tapping when listening on the bell housing of the trans. This will drive me nuts...
What you think you hear, and what it actually is, can be a heart breaker, or a "whew!" wipe of the brow. After a new BBB build, install and break in run (lot$a doller$), with open headers (can you say: "WHAT? I CAN'T HEAR SHTUFF!!!" then drive down and have the exhaust installed, drive home and back into the garage and her this?!!!! And the bottom of you stomach hits the floor as you think: "OMG! ROD KA-KNOCKING!!!" Yep. Nearly $6K on buying block, TA Part$, machine work, all my time and labor assembling, install, and thinking I have a rod taking heading south for the winter, and being an old retired boomer on a fixed income and limited time in the last inning, I do not need this to be happening.... Turns out, than I did not clearance the aftermarket pan, and the front most counterweight is lightly tapping against the pan. (CLICK ON THAT THING DOWN THERE!!!!) https://www.wootmonkey.com/upload/2020/06/05/20200605212808-36c89154.mp4 I used a stud welder and pulled the pan where my finger pressed and the knock went away. But I was finally able to sleep, without tossing and turning thinking the bottom end was going to "Hiroshima" the next time I put my foot in the a$$ of the carb. So, get a stethoscope and see if it is a timing chain, fuel pump arm, valve train, oil pan interference, belt chirp, pully, PS, water pump bearing, exhaust manifold leak, or some simple thing before you pull your hair and engine out.
